Cascading Auto-oxidative Biproline Guanylations Form Optically Active Dispacamide Dimers and Permit an Eight-Step Synthesis of (-)-Ageliferin.

A nickel catalyzed synthesis of isomeric 3,3'-biproline esters is described. When those materials are doubly acylated with the acid chloride of pyrrole-2-carboxylic acid, they become susceptible to auto-oxidation in the presence of guanidine. Through proper staging of reaction conditions, it is possible to initiate two consecutive oxidative guanylations… CONTINUE READING